Air-cooled blast-furnace.



R. H. STEVENS.

AIR. GOOLBD BLAST FURNACE.

APPLICATION FILED SEPT. 24, 1912.

1,074,097, Patented Sept. 23, 1913.

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RICHARD H. STEVENS, 0F MU'Nl-IALL, PENNSYLVANIA.

AIR-COOLED BLAST-FURNACE.

LOW 1,097.

To all whom it may concern Be it known that I, RICHARD H. S'rnvnNs, a citizen of the United States, residing at Munhall, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Air- Cooled Blast-Furnaces, of which the following is a specification.

My invention relates to the construction of blast furnaces, and more particularly to the construction of the means employed in cooling the shaft lining of such furnaces and in handling the compressed air used for cooling the furnace shaft and in supplying air to the furnace stoves in supplying the hot blast used in such blast furnaces.

One object of my invention is to provide a blast furnace of improved construction having novel means for handling and con veying the air used in forming the hot blast whereby the cold air compressed in making the hot blast is utilized in cooling the Walls and lining of the furnace shaft, an interchange of heat is effected in the shaft cooling operation, and the so-heated air is then further heated to the high temperature of the hot blast in the hot blast stoves of the blast furnace.

Another object of this invention is to provide a blast furnace of novel COIlStlllCtiOIl having a shaft jacket of novel construction in which the hollow metal jacket for the furnace shaft lining is connected by the cold blast mains or conduits to the hot blast stoves and blowing engines or compressors forming part of the furnace equipment.

Still further objects of the invention will appear hereinafter as the invention is more fully described and claimed.

The drawing forming part of this specification is a side elevation showing the blast furnace, furnace stoves and blast mains, the furnace being illustrated in section.

In the drawing, 2 designates a blowing engine house in which the blowing engines are located, by means of which the air forming the cold blast is compressed, and 3 is a blast furnace having a series of hot blast stoves 4, the blowing engine house, the furnace and the hot blast stoves being located and arranged relatively, in the usual well Specification of Letters Patent.

App1ication filed September 24, 1912.

Patented Sop t. 23, i 913.

Serial No. 722,096.

known manner. The blast furnace 3 is provided with the customary refractory lining 5, surrounded by a metal shell or jacket having double walls 6 and 7 forming an annula air space or chamber 8 thercbetween extending from the bosh line to the gas oil'- takes of the furnace. A cold blast main 9 conducts the cold compressed air from the blowing engines within the engine house 2 to a bustle pipe 10 which surrmulds the lower portion of the annular jacket around the shaft of the furnace 3 at about the level of the bosh line. A series of branch outlet pipes 10 are employed to conduct the cold blast at a plurality of points from the busllc pipe 10 into the lower portion of the annular chamber 8 formed by the double jacket walls (3 and 7, and when required the branch pipes 1.0 are provided with suitable gate valves.

At the top of the furnace, somewhat below the level of the gas ofl'takcs 11 a bustle pipe 12 is located, which is provided with a series of branch outlet openings 13 connecting the upper end of the annular chamber 8 with the bustle pipe 12. The bustle pipe 12 is connected by a cold blast main 1 1 with the furnace stoves ll, valve-controlled cold blast inlets 15 being provided on the cold blast main 141- to conduct the cold blast to the top of each of the three-pass stoves shown. The cold blast inlets 15 may be of any of the known constructions of which there are several. The cold blast entering the stoves t is heated in its passage therethrough to a high ten'iperature in the usual manner and the highly heated hotblast is conducted from the stoves through the valve-controlled hot blast branches 16 to the hot blast main 17 which leads to the bustle pipe 18 surroumling the bush of the furnace 3 below the bosh line. The hot blast is conducted from the bustle pipe 18, at a plurality of points, by means of the penstocks 1f), blow pipes 20, through the furnace twyers 21 and into the furnace 3, in the usual manner.

The blast furnace has the usual tapping hole and cinder notch, and the top of the furnace is provided with a hopper 23 and closing bell 241 of any known construction.

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The gas otl'takes 11 are connected to a downcomer in the usual manner, and a bleeder pipe 26 and bleeder valve are provided on one or more of the gas ciftakes 11.

By reference to the drawing it will be seen that instead of having a series of water cooled plates inserted in rows at separated intervals in the height of the furnace shaft, the refractory lining 6 in the shaft of the furnace is maintained in the desired cooled condition through the medium of the cold blast in its passage from the blowing engine house through the annular chamber 8 formed by the shaft acket, and then to the hot blast stoves 4 The cold blast in passing a from the lower end to the upper end of the annular chamber 8, into the cold blast main 14, extracts heat from the refractory lining 6 and the temperature of the air is thereby raised during its passage through the chamber 8. The so-heated air passing from the chamber 8 then passes through the cold blast main 14 and enters the hot blast stoves in a pre-heated condition, and in this way the air serves a double purpose in cooling and maintaining the shaft lining in the desired cool condition, while the heat extracted by the air during its passage through the annular acket 8 surrounding the furnace shaft lining 6 raises its temperature so that the air or blast will enter the cold blast stoves in a pre-heated condition and will require a correspondingly less amount of heating within the hot blast stoves. The partly heated air, in passing through the hot blast stoves 4c, is then readily heated to the high temperature necessary in forming the hot blast for the furnace, and the hot blast is led from the stoves 4 through the hot blast main 17 into the bustle pipe 18 and is delivered from the bustle pipe through the penstocks 19, blow pipes 20 and twyers 21, into the furnace 3 in the desired highly heated condition in the ordinary manner.

The advantages of my invention will be apparent to those skilled in the art. By leading the cold blast from the blowing engine house through the annular chamber formed by the metal jacket surrounding the shaft lining of the blast furnace, the air is heated before entering the hot blast stoves and the heating of the blast within the hot blast stoves is lessenedby an amount equal to the heat added in passing through the jacket 7. The passage of the cold air through the annular chamber formed by the metal jacket surrounding the shaft lining maintains the lining at the required low temperature in a cheap and efficient manner. The air entering the top of the stoves at a high temperature, the time required, and cost of transforming the cold blast to the high temperature of the hot blast, is lessened and reduced.

in maintaining the furnace in the desired cooled condition is lessened and reduced.

Modifications in the construction and arrangement of the apparatus may be made without departing from my invention as defined in the appended claims.

I claim:

1; In a blast furnace plant, the combina tion with the furnace hot blast stoves, of a furnace having a hollow metal shell or jacket forming the furnace shaft, and means for conducting the air forming the cold blast through said hollow metal jacket, in its passage to said stoves, to thereby effect an interchange of heat which cools the metal jacket and preheats the cold blast in passing through said jacket preparatory to further heating in said hot blast stoves. V

2. In a blast furnace plant, the combination with the furnace hot blast stoves, of a furnace having a hollow metal shell or jacket forming the furnace shaft, and having a refractory shaft lining, and means for conducting the air forming the cold blast through said hollow metal acket in its passage to said stoves, to thereby effect an interchange of heat which cools the metal jacket and refractory lining, and preheats the cold blast in passing through said jacket preparatory to further heating in said hot blast stoves.

3. In a blast furnace plant, the combination with the furnace hot blast stoves of a furnace having a refractory shaft lining and a hollow metal jacket or shell surrounding said lining, means for conducting the air forming the cold blast into one end and out of the opposite end of said hollow acket, in its passage to the furnace stoves, whereby an interchange of heat is effected cooling the shaft jacket and lining and preheating the cold blast in passing the cold blast through said jacket preparatory to further heating in said hot blast stoves.

4. In a blast furnace plant, the combination with the furnace hot blast stoves of a furnace having a hollow metal shell or jacket forming the furnace shaft, means for conducting the air forming the cold blast into the lower end and out of the upper end of said hollow metal jacket in its passage to the hot blast stoves, to thereby effect an interchange of heat which cools the metal jacket and preheats the cold blast in passing through said jacket preparatory to further heating in said hot blast stoves.

5. In a blast furnace plant, the combination with the furnace hot blast stoves of a furnace having a refractory shaft lining and a hollow metal jacket or shell surrounding said lining, bustle pipes each having a plurality of branches connecting the bustle pipes to the hollow metal jacket, means for supplying air forming the cold blast to one of said bustle pipes, and means connecting the other bustle pipe to the furnace stoves whereby the cold blast is delivered into said hollow metal jacket in its passage to the stoves to efi'ect an interchange of heat which cools the jacket and jacket lining, and preheats the air of the cold blast preparatory to further heating in said hot blast stoves.

In testimony whereof, I have hereunto set my hand.

RICHARD H. STEVENS. Witnesses:

WV. H. Comm'rr, J. A. HAMILTON.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, I). 0. 

